Azo contact prints developed in PC-TEA

I am in the midst of performing some comparative tests of developers on the current batch of Canadian manufactured Grade 2 8x10 Azo. The developers are:
1. Ansco 130 with 1 gram/liter KBr
2. Pat Gainer's PC-Tea (ascorbic acid/phenidone/triethanolamine), with and without KBr and Benzotriazole and with added sodium carbonate
3. Donald Miller's Phenidone, pyrogallol, pyrocatechol developer (PPPD), with and without KBr and Benzotriazole.
4. Michael Smith's Amidol developer prepared with a liquid stock solution of Amidol in propylene glycol (it'll be about 20 days old by then).

The negatives I am printing are all 8x10 Efke PL 100, semi-stand developed in Pyrocat-HD.

As a baseline, I printed all negatives (6) and developed in fresh Ansco 130 with 1 gram of KBr per working solution liter of developer. All negatives printed ok on the Grade 2 (but 2 negs needed a little bit lower contrast paper/development). The image color is slightly on the brown side, shadow detail and densities are excellent.

I diluted the PC-TEA 1:15 as a starting point and added no KBr or Benzotriazole for the first set of prints. The result was a very soft, warm toned print with plenty of fine detail. The paper contrast dropped to about a Grade 1+.

I added 1 ml of 10% KBr with no apparent effect. I then added 1 ml of 10% Benzotriazole (which had a slight effect on the image tone). I added an additional 1ml of 10% Benzotriazole, which slowed the appearance of the developing image and shifted the image color to blue/black (colder than the Ansco 130 + KBr).

I was not getting the good blacks that I was getting before adding the Benzotriazole. The resulting paper contrast remained around a 1+. I decided that the developer probably needed some more alkali and added a spoonful of sodium carbonate (about 10 grams to my liter of working developer). That did the trick, good cold blacks and about a 1.5 contrast.

This looks like a very useful paper developer. Split development with one set of liquid stock solutions? - looks possible.

Update:
Today I developed my Azo in Donald Miller's Phenidone, pyrogallol, pyrocatechol developer (PPPD), with and without KBr.

Without KBr I got good tonality and very dense, warm blacks (with a slight reddish tone). The developer was very active without KBr!

After developing 8 8x10s I added KBr (twice as much as I intended - and the formula calls for). The printing time increased by a factor of 5. The effective paper contrast dropped to about Grade 1. In spite of all this, I managed to get one quite good print.

When I developed the next print, I found that the developer was dying (after 16 prints from 1 liter of working solution). I threw in a teaspoon of sodium carbonate and tried another print - could only get a very weak image to appear.

I'll try again - with the right amount of KBr this time.

The PPPD developer heavily stained my (white Cesco) developer tray.

I am comparing the blacks and tonality of my Azo prints against the blacks in George Provost's Azo/Amidol print "Roots."

My best prints so far are the ones I developed in Ansco 130 with 1 gram of KBr added to the working developer. George Provost's blacks are better - almost 3 dimensional.

I will make one more run with PPPD, then on to Michael Smiths Amidol formulation.

Tom, my experience with using Gainer's ascorbic formulas for paper indicate that they need an excess of ascorbic acid or ascorbate to last in the tray and give good blacks. Gainer recommends 40 times more AA than phenidone for film because this is the ratio at which the solution gives maximum activity for a minimum amount of developer. That's fine for one-shot film processing. But in a tray, exhaustion and aerial oxidation starts soon as you begin. An excess of ascorbate will help delay that and maintain activity.

The only sign of reduced developer activity was when (after 10 8x10 prints) I added Benzotriazole (and this was expected). The working developer remained at that lower activity level until I "kicked it" with a teaspoon of sodium carbonate.

It remained at that higher level of activity (8 more 8x10 prints) until I poured it down the drain.